Filter elements which use filter media having spacer arrangements between panels of the media for filtering particulate bearing fluid streams are known in the art. However, the spacers tend to be inserted elements which increases the cost of filter media and can compromise the reliability of the filter media. This is because inserted spacers can become dislodged and damage the filter media if on the upstream or dirty side of the filter media. If on the clean side of the filter media, the spacers can become dislodged and possibly damage the machinery served by the filter media.
With respect to air filters for internal combustion engines, there is continuing need to increase dirt holding capacity while reducing restriction. Preferably, this is accomplished as inexpensively as possible. With respect to filters for diesel trucks, increased dirt holding capacity with acceptable restriction levels is currently only obtainable with cylindrical filters used for medium and heavy duty applications. In order to conserve space in engine compartments panel air filters are now being employed, but panel air filters have encountered the aforementioned problems of reduced dirt holding capacity and relatively high restriction. Accordingly, there is a need for improvement in panel air filters.